In the interests of providing higher speed, the art has searched for dielectric layers having a lower dielectric constant. It has been suggested in an article by J. Ida, et al entitled "Reduction of Wiring Capacitance with New Dielectric SiOF Interlayer Film for High Speed/Low Power Sub-Half Micron CMOS", 1994 Symposium on VLSI Technology Digest of Technical Papers 0-7803-19212-4/94 IEEE, that the use of C.sub.2 F.sub.6 in connection with TEOS (Si(OC.sub.2 H.sub.5).sub.4) may provide a silicon dioxide (oxide) layer with fluorine doping (fluorosilicate glass or F-glass) that provides such a lower dielectric constant. Another suggestion in an article by Fukada and Akahori entitled "Preparation of SiOF Films with Low Dielectric Constant by ECR Plasma Chemical Vapor Deposition" in Extended Abstracts of the 1993 International Conference on Solid State Devices and Materials, Makuhari, 1993 pp. 158-160, has been the use of silicon tetrafluoride (SiF.sub.4) in connection with O.sub.2. An article by Anand, et al entitled "Fully Integrated Back End of the Line Interconnect Process for High Performance ULSIs" in the 1994 VMIC Conference 1994 ISIMC--103/94/0015, suggests the use of CF.sub.4 and C.sub.2 F.sub.6. The C.sub.2 F.sub.6 method renders a film that is susceptible to the absorption of water, and the SiF.sub.4 ECR deposition method is susceptible to outgassing of hydrogen fluoride or fluorine, since the excess F atoms dissociated in the high density Electron Cyclotron Resonance plasma are incorporated in the F-SiOx network as weakly bonded fluorine. When more water is absorbed and F* is lost, the fluorine forms HF, which corrodes metallization. The art has not yet found a satisfactory method of forming a stable film of F-glass with sufficiently high fluorine content to significantly lower the dielectric constant and increase gap-fill capacity.